This switch is located at Channel>Channel Settings>Shopify Settings tab.
If you enable this switch, SA will only send all Tags (Bullet Points, Target Audience, Search Terms, Used For) when the products are initially created on Shopify. This is useful when you don’t intend to update Tags after creation and don’t want to send Tags in each product data update. Sending tags in creation allows the next system scheduled product data update to be processed faster to the remote channel.
IMPORTANT NOTE: This setting will be applied for the products that were not created in the remote Shopify channel yet.